1. Field of the Invention
The invention relates to a ground-working machine with a roller-like, transverse kirving tool. Machines of this type are known for levelling the roadway in road building, for the demolition of buildings and plants, the excavation of ditches and pits, the removal of root structures and rock formations, and also for the removal of rocks in tunnel construction and the removal of material in mines, for example gypsum, coal or salt mines. In the machines for roadway building, the axis of the kirving tool is integrated in a vertically adjustable, but non-pivotable manner in a vehicle provided with a crawler drive.
2. State of the Art
U.S. Pat. No. 6,725,579 discloses an excavation machine which is designed as a crawler vehicle on which there is arranged an excavation arm which is arranged at the back in the direction of travel. The excavation arm is divided into a first region close to the vehicle and a second region remote from the vehicle. The first region is vertically pivotable about a horizontal axis. The second region comprises a kirving tool which has in a known manner a chain drive and, on both sides of this chain drive, a kirving roller. The second region of the excavation arm is pivotable in relation to the first region of the excavation arm about an axis directed in the direction of the arm. This allows the transverse inclination of the worked substrate to be adapted.
In most conventional machines which are also heavy apparatuses with a crawler drive, the roller-like kirving tool is fastened to an arm, which arm is pivotable about a horizontal axis in order to define the working height of the kirving tool. The arm is often also pivotable about a vertical axis in order to extend the working region in width, i.e. transversely to the direction of travel of the machine. Machines of this type are expedient, in particular, in tunnel construction, as they offer the possibility of enlarging the tunnel profile, both in height and in width, to the planned dimensions.
The term “transverse kirving tools” refers to kirving tools having an axis of rotation extending transversely to the kirving direction. Propulsion thereof in the direction of the axis of rotation is possible merely to a limited extent, that is to say, provided that the kirving depth corresponds substantially to the spacing of the tips of the kirving chisels from the roller surface to which they are fastened. Generally speaking, transverse kirving rollers are formed by two roller-like kirving bodies which lie on a common roller axis, are equipped with kirving chisels and between which the drive and the suspension are arranged.
Kirving tools of this type can also be fastened to a dredger arm. They can be mounted there, as required in each case, in two directions lying perpendicularly to each other. The roller axis therefore lies perpendicularly to a vertical plane through the dredger arm, or else parallel to this plane.
Machines for milling off the road surface are known from the two Offenlegungsschriften DE 24 11 244 and DE 2 264 710. The machines possess a running gear with a drive motor and a milling roller driven via a cardan shaft. During operation, the milling roller is wider than the chassis. For the pure travelling mode of the machine, the milling roller is detachable from the drive and pivotable, together with a mount, through 90 degrees into a rest position in which the entire milling roller is located within the outer longitudinal delimiting lines of the machine. This prevents the excess width, which has a beneficial effect on the degree of utilisation, of the milling roller from becoming disruptively noticeable during transportation.
The known machines are not suitable for building paths in areas which are difficult to access. They are too large and insufficiently flexible. Paths, for example footpaths, follow narrow curves, which these known devices have difficulty following, and have a width of 1 m to 1.5 m, so that it is not possible to travel thereon using machines of this type which require a roadway of at least approximately 2 meters.
It would therefore be an advantage to provide a ground-working machine which can be used to build even on footpaths and the like.